Assessment of the Seismic Response of Concentrically-Braced Steel Frames

Shake table assessment of gusset plate connection behaviour in concentrically braced frames

“…In the experimental programme, the behaviour of the test frame and each pair of brace-gusset plate specimens was examined under three different levels of earthquake excitation to evaluate elastic frame response, brace buckling and yielding effects, and brace fracture (Broderick et al 2015). The three earthquake intensities in these tests were characterised as an operating basis earthquake (OBE), a contingency level earthquake (CLE) and a maximum credible earthquake (MCE).…”

“…Material characteristic strengths were obtained by performing coupon tests on the brace tube and gusset plates, with the average tensile yield strengths of both the bracing and gusset plate elements presented in Table 2. Further details on the strength capacities and testing details for all specimens can be found in Broderick et al (2015).…”

“…Differences in the amplitudes of the drift responses in these test pairs are largely attributable to the different natural periods/stiffnesses and actual table pga values shown in Table 3. In this regard, the frame stiffness indicated by the natural period measured immediately before each test run are more relevant than that given by the initial natural period, with the differences between these two values being associated with the unique response histories experienced in the preceding low-and mediumlevel excitation tests (Hunt 2013, Broderick et al 2015. Some of the drift time-histories shown in Figure 7 display significant lengthening in natural period during individual tests (e.g.…”

“…In all tests, local deformation demands in the right-hand brace-gusset plate specimens were measured using strain gauges. No strain gauges were placed on the left-hand brace to facilitate a photogrammetry measuring technology system (Broderick et al, 2015). Strain gauges were positioned in a standard layout on the brace and gusset plates, as shown in Figure 15, with each strain gauge identified by a number prefixed with 'SG'.…”

Fuzzy-driven strategy for fully automated modal analysis: Application to the SMART2013 shaking-table test campaign

“…Such methodologies have proven effective in the case of long-term monitoring where single structures are instrumented with permanent sensing devices; in that case the time spent for correctly adapting the thresholds to the problematic is of less importance compared to monitoring time. However, the seismic tests conducted in the TAMARIS/CEA facility impose a different context: the zoology of experimental systems is vast (reinforced concrete building [20], steel-frame structures [21,22], timber-frame construction [23], tanks [24], etc. ), the ground motion tests numerous, involving possibly different configurations and a wide variety of sensors.…”